[IP+NF] modular SSA optimizer + split Thumb backend + RP2350 fixes

.gitignore

@@ -3,6 +3,7 @@
 .#*
 *.o
 *.so
+*.elf
 *.a
 *.exe
 *.dll
@@ -85,3 +86,19 @@ tmp/
 
 .venv
 bin/
+.yasos-build
+tests/ir_tests/pch_header_check
+tests/ir_tests/pch_usage_check
+pch/
+config.h.cross
+.opencode
+test.txt
+tests/ir_tests/dump_ir.txt
+tests/ir_tests/dump.txt
+tests/ir_tests/dump_fine.txt
+tests/ir_tests/dump_ir_fine.txt
+.aider*
+.claude
+.cache
+scripts/.disasm_cache.json
+scripts/.disasm_cache.pending.json